Mobariv Zadran, spokesman for the Khost governor, confirmed the explosion but had no further details.

Earlier, the six Afghan policemen were killed in the roadside blast that occurred about 11 a.m. (2:30 a.m. ET) in the Darayoum district of Badakhsan province, said Baz Mohammad Ahmadi, the provincial governor. The mine struck a police vehicle patrolling as part of a counter-narcotics program, he said. Drug smugglers are believed to have planted the mine.

The counter-narcotics program started six months ago, and will continue until the province's level of narcotics is at zero, Ahmadi said.

Separately, four Taliban leaders were killed in the Baharak district of Badakhsan province in a National Directorate Security staff operation early Sunday, Ahmadi said.